preparing for a real life deep impact. >> keep it right here, america. >>> from new york city, this is ni "nightline" with cynthia mcfadden. >> good evening, and thank you for joining us. we begin with break news from alabama. it's a scene of joy and relief tonight, as the carnival cruise ship that lost power five days ago has finally reached port in mobile, alabama, are 4,200 people aboard. over the past few days, many passengers have sent messages describing nightmarish conditions. food shortages, lack of running water and sewage problems. tonight, frustrated passengers said the experience has been highly stressful, though many praise the boat's staff for doing their best under difficult circumstances. stay with abc news for all the latest. >>> but for now, we turn halfway around the world to the shock waves being sent by the arrest of famed olympian charged with murdering his glamorous model girlfriend in the wee hours of this valentine's day morning. >> reporter: oscar pistorius and reeva steenkamp were one of the world's hot couples. think david and victoria, or brad and angeli